Method for making truss members

ABSTRACT

A method and apparatus for forming truss members which comprise oppositely disposed channel members and struts interconnected to one another by alternately extending apices wherein the apices are welded to the channel members. The method and apparatus provides for simultaneously forming channel members from a pair of endless strips and the strut members from an endless third strip, guiding the channels in a predetermined relation to one another with the third strip therebetween and thereafter welding the apices to the channel members.

METHOD FOR MAKING TRUSS MEMBERS Inventor: Melvin L. Ollman, Detroit, Mich. Assignee: C-O, llnc., Detroit, Mich.

Filed: Apr. 11, 1973 Appl No.: 350,158

Related US. Application Data Continuation-impart of Ser. No. 129,040, March 29, 1971, abandoned.

US. Cl 29/155 R, 29/47l.l, 29/480 lnt. Cl B235) 17/00 Field of Search 29/47l.1, 475, 480, 155 R,

References Cited UNlTED STATES PATENTS 9/1932 Wallen 219/107 X 9/1932 White et al. 219/107 X 11] 3,827,117 Aug. 6, 1974 3,288,977 11/1966 Keller ..219/79 3,641,303 2/1972 Collins 219/56 Primary Examiner-Richard B. Lazarus Attorney, Agent, or FirmBarnes, Kisselle, Raisch & Choate 5 7 ABSTRACT A method and apparatus for forming truss members which comprise oppositely disposed channel members and struts interconnected to one another by alternately extending apices wherein the apiees are welded to the channel members. The method and apparatus provides for simultaneously forming channel members from a pair of endless strips and the strut members from an endless third strip, guiding the channels in a predetermined relation to one another with the third .strip therebetween and thereafter welding the apices to the channel members.

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1. In the continuous method of making truss members which comprises forming a pair of longitudinally extending endless strips into channels having a base and flanges, forming a third longitudinally extending strip into a plurality of interconnected struts, each strut comprising non-flat portions connected to one another by flat portions, bending the third strip at the said flat portions to form alternately extending apices and interconnected struts, bringing the channels into a generally adjacent parallel relationship with the third strip extending therebetween with alternate apices contacting opposite channels, and bonding the apices to said channels, the improvement which comprises the steps of cutting both side edges of each of the pair of strips partially through the width thereof in at least two points in portions of said strips which are spaced longitudinally at predetermined points along the length thereof and which cut portions are transversely aligned with respect to the longitudinal axes of said pair of strips such that said cut points are intermediate the points where said successive alternate apices of said third strip contact said opposite channels, cutting through the entire width of the channels and the strut of the assembled truss members intermediate said cut points to form a truss section including free ends on said channels and struts, and thereafter bending the free ends of the channels and struts Inwardly toward one another at said transversely aligned cut points of said flanges.
 2. The method set forth in claim 1 wherein said cutting of said side edges of said pair of strips is performed in advance of said forming said pair of strips into said channels.
 3. The continuous method of making truss members which comprises intermittently feeding three longitudinally extending endless strips successively to a first cutting station, a forming station, a bending station, a bonding station, and a second cutting station, simultaneously forming a pair of said strips into channels having a base and flanges and the third strip into a plurality of interconnected struts at said forming station, each strut comprising non-flat portions connected by flat portions, thereafter bending the third strip at said flat portions to form alternate extending apices and interconnected struts at said bending station, thereafter bringing the channels into a generally adjacent parallel relationship with the third strip extending therebetween and alternate successive apices contacting opposite channels, cutting both side edges of each of the pair of strips at said first cutting station partially through the width thereof in at least two points in portions of said strips which are spaced longitudinally at predetermined points along the length thereof and which cut portions are transversely aligned with respect to the longitudinal axes of said pair of strips such that said cut points are intermediate the points where said successive alternate apices of said third strip subsequently contact said opposite channels, bonding the apices to said channels at said bonding station, thereafter cutting through the entire widths of the channels and the strut of the assembled truss members intermediate said cut points to form a truss section having free ends on said channels and struts at said second cutting station, and thereafter bending the free ends of the channels and struts inwardly toward one another at said aligned cut points of said flanges.
 4. The continuous method of making truss members which comprise oppositely disposed channel members and struts interconnected to one another by alternately extending apices wherein the apices are welded to the channel members, which method comprises intermittently moving a pair of longitudinally extending endless flat channel forming strips and a flat strut forming strip to a forming station, a bending station, a bonding station, simultaneously pressing the channel forming strips and the strut forming strips at said forming station to form the channel forming strips into channel shapes that are oppositely disposed and positioned in the same general relationship to one another as in the assembled truss and to form the strut forming strip into a succession of shapes which have short flat portions connected by longer non-flat intermediate portions which are generally U-shaped in cross section midway along their length and gradually become shallower and wider toward the flat portions, thereafter moving said strut forming strip to bring each successive pair of struts to a bending station, thereafter bending said previously formed pair of struts at said flat end portions with respect to the remainder of said strip to provide alternating extending apices disposed along a longitudinally extending line at said bending station, maintaining the general relationship of said channel members in their movement from said forming station to said bonding station, and bonding the apices to said channel members at said bonding station, cutting both side edges of each of the pair of channel forming strips partially through the width thereof in at least two points in portions of said strips which are spaced longitudinally at predetermined points along the length thereof and which cut portions are transversely aligned with respect to the longitudinal axes of said pair of strips such that said cuT points are intermediate the points where said successive alternate apices of said third strip contact said channels at a first cutting station, thereafter cutting through the entire widths of the channels and the strut of the assembled truss members intermediate said cut points to form a truss section having free ends on said channels and struts at a second cutting station, and thereafter bending the free ends of the channels and struts inwardly toward one another at said aligned cut points of said flanges.
 5. The method set forth in claim 4 wherein said step of cutting said side edges of said pair of strips is performed in advance of said forming of said pair of strips into channels.
 6. The method set forth in claim 5 wherein said step of cutting through the widths of said channels and strut is achieved by positioning cutting means along the assembled truss member and moving said cutting means transversely of the longitudinal axes of said assembled channels and struts, including the steps of shifting the point of cutting partially through the side edges of said pair of strips longitudinally first in one direction and then in the opposite direction and shifting the cutting means longitudinally first in one direction and then in the opposite direction a corresponding amount to said first-mentioned shifting.
 7. The method set forth in claim 3 wherein said step of cutting through the widths of said channels and strut is achieved by positioning cutting means along the assembled truss member and moving said cutting means transversely of the longitudinal axes of said assembled channels and struts, including the steps of shifting the point of cutting partially through the side edges of said pair of strips longitudinally first in one direction and then in the opposite direction and shifting the cutting means longitudinally first in one direction and then in the opposite direction a corresponding amount to said first-mentioned shifting. 